Domain Names 101

How do Internet Domain Names Work?

The idea of Internet domain names is no longer a new thing -- domain names are now woven into the fabric of modern society, with "dot com" appellations appearing in TV and print advertising, on billboards, and even on bumper stickers. Domain names are hot commodities that can be worth thousands to hundreds of thousands of dollars and are fast becoming a primary link between businesses and their customers. If you're planning on getting a domain name for your enterprise, it's good to learn some basic facts about how domain names work.

You're probably already familiar with ".com" domain names -- they're everywhere, after all. But what about domain names ending in something else, such as .net, .org, or even .tu? That last little bit of an Internet domain name -- the part after the last period -- is called the top-level domain, or TLD. Think of it as the primary category of the name. The original intent was that all domain names in a particular TLD would be somehow related. The major TLDs are ".com," ".net," ".org," ".edu," ".gov," and ".mil."

These major TLDs are known as generic TLDs, because they cover very general categories. Within a given TLD is the set of second-level domain names. For example, 'gonamesecure' in, and 'trynamesecure' in are second-level domains. A given computer serving a particular kind of information within an organization may have a third level domain name, such as the 'www' in for NameSecure, LLC's web server, or the 'mail' part of for the Name Secure mail server.

Within the generic TLDs, only second-level names are registered. The organization that registers the second-level name can have as many additional levels of the domain names as it wants, using whatever names it likes above the second level (e.g. Few organizations go beyond the fourth or fifth level with their names.

Within the generic TLDs, individuals and businesses can register domain names under ".com," ".net," and ".org," which are sometimes called the Big Three. The other generic TLD (".edu," ".mil," and ".gov") are restricted to organizations in higher education, the military, and the government, respectively.

There is also another lesser-used set of TLDs on the Internet that are based on country codes. For example, ".uk" is the country-code TLD for the United Kingdom. This geographically-oriented TLD system is not as popular as the generic system, and is considerably more complicated.

Related Links
The official definition of domain name system
Information about country code domains
The US country-code domain name system
Generic TLDs
  • .aero

    Restricted to certain members of the global aviation community, sponsored by Societe Internationale de Telecommunications Aeronautiques SC (SITA)

  • .biz

    Restriceted to businesses, operated by NeuLevel

  • .com

    Unrestricted, operated by VeriSign Global Registry Services

  • .coop

    Restricted to cooperatives, sponsored by Dot Cooperation LLC

  • .edu

    Reserved for educational institutions at the college level

  • .gov

    Reserved for U.S. government agencies

  • .info

    Unrestricted, operated by Afilias Limited

  • .mil

    Reserved for U.S. military organizations

  • .museum

    Restricted to museums and related persons, sponsored by the Museum Domain Management Association (MuseDoma)

  • .name

    Restricted to individuals, operated by Global Name Registry

  • .net

    Unrestricted, operated by VeriSign Global Registry Services

  • .org

    Unrestricted, operated by Public Interest Registry

  • .pro

    Restricted to licensed professionals, operated by RegistryPro

Registrations R Us

Although the Internet and the Big Three TLDs (".com," ".net," and ".org") were invented in the United States, companies and individuals from anywhere in the world can register domain names within them. They can do this by contacting a domain name registrar, of which NameSecure is one. When registering a domain name, a registrar records the registrant's name, address, and other pertinent contact information. Selected contact information is stored in a database called the WHOIS database. There is one giant WHOIS database called the InterNIC WHOIS that contains all the names for all ".com," and ".net," TLDs. You can get the WHOIS information for any registered ".com," and ".net" name by performing an availability search using the search box above. (Click the "Registration Info" link in the domain name search results to get a domain name's WHOIS information.)

You pay a fee to the registrar when you register a domain name, which makes you the registrant of record for that domain name. However, intellectual property law applies to domain names, so just registering a name doesn't necessarily mean you are legally entitled to use it. If the name conflicts with a registered trademark or can be confused with another organization's name, you may not be able to use or keep the name.

CONTINUED: Names to Numbers